The present invention relates to improvements in processing baled waste material containing waste paper articles of various types for recycling the contents of the bale to recover a maximum amount of cellulosic fibers from the various categories and types of paper fiber containing articles that are contained in the bale of waste material with a minimum degradation or damage to the recovered paper fibers.
To enhance the conservation of material resources, particularly forest land, and to reduce the amount of waste material that is disposed in ever increasing landfill areas, widespread interest has developed in recycling waste matter of which a significant portion comprises waste paper articles of assorted types and compositions for recovering the fibers of the waste paper articles that are used in producing recycled paper products. Waste matter of various categories normally is packaged as tightly compacted bales of considerable size and weight for ease of handling and storage. The nature of these tightly compacted and very heavy bales presents serious problems in processing the miscellaneous tightly compacted contents of the bale in an economical and efficient manner such that the fibers recovered from the miscellaneous types of waste paper articles in the bale are of a high quality and free of contaminants with minimal damage to the fibers from being cut, broken or shortened in the recycling defibration operations. Our U.S. Pat. Nos. 5,147,502 and 5,203,966 discuss this problem at considerable length and disclose measures by which the contents of the tightly compacted bales of waste material can be subjected to a pre-recycling conditioning treatment which causes the fibers of waste paper articles contained in the tightly compacted bale to become swollen and the fiber bonding forces substantially weakened prior to defibration of the waste paper articles and separation of the fibers into a liquid suspension slurry. As discussed in our aforesaid patents, this pre-recycling conditioning treatment involves a thorough wetting impregnation of the contents of the compacted baled waste material by discharging a high velocity jet of cellulosic fiber softening and swelling fluid into the interior of the bale as saturates the waste material in the bales with the fluid to a degree as establishes the desired debonding swelling of the fibers of the waste paper articles in the baled waste material. This debonding swelling reduces the bonds between the fibers of the waste paper articles and between the waste paper fibers and contaminants that form a portion of the waste paper articles. Other previously known measures by which the contents of compacted baled waste material can be subjected to pre-recycling conditioning treatment comprise the submergence of the baled waste material in a water-filled trough for a protracted period prior to breaking up the bale and defibrating the water saturated waste paper as in the manner disclosed in U.S. Pat. No. 4,458,845 of Marcalus, et al. However, this old procedure has the serious disadvantage of requiring an excessive time period for the waste paper contents of a tightly compacted bale to become sufficiently saturated with the debonding fluid. Entrapped air within a bale submerged in a water filled trough prevents a high degree of saturation of the waste paper in the bale within a reasonable period of time.
Waste paper contained in baled waste material normally includes a wide variety of types of cellulosic fiber containing articles of which the fibers of some articles are substantially free of contaminants such as wax, plastics, latex, asphalt or other non-fibrous matter. Relatively uncontaminated fiber articles of this nature are broke, post-consumer paper products such as corrugated boxes, discarded office papers, stationery, toweling, etc. The fibers comprising other types of paper articles contain contaminated matter in which the fibers and their outer walls have been penetrated to various degrees by and contain non-fibrous contaminants in which the contaminants provide special qualities to the fibers of the article such as wet strength. Other types of paper articles have fluid barrier coated surfaces in which the contaminant coating establishes a barrier to the penetration of fluids into the interior fibrous portion of the article. Typical of this latter type of article, and which presents serious problems in penetration of a debonding fluid into the barrier coated fibrous matter, are milk cartons, aseptic juice boxes, freezer wrap, foil laminated cartons, coated sanitary products, moisture barrier shipping sacks, etc. After the defibration separation out of the relatively uncontaminated cellulosic fibers of waste paper contained in bales subjected to the pre-recycling conditioning treatment procedures disclosed in the above mentioned patents, it has been the general practice to dispose the non-debonded and contaminant containing or contaminant coated fibrous matter to landfill along with the non-fibrous waste matter and contaminants contained in the bales due to the difficulty of a further separation out of the cellulosic fibers of waste paper articles containing a high degree of contaminated fibrous matter or whose surfaces are coated with a fluid barrier contaminant.